plural vs knee breeches

plural and knee breeches both are nouns.

Word	Noun	Adjective	Verb	Adverb
plural	Yes	Yes	No	No
knee breeches	Yes	No	No	No

plural (noun)	knee breeches (noun)
the form of a word that is used to denote more than one	(used in the plural) trousers ending above the knee

plural (adjective)	knee breeches (adjective)
grammatical number category referring to two or more items or units
composed of more than one member, set, or kind